Aricent Technologies Technical Interviews Question Bank continued from Part 4
Q-21. Give a brief description about circuit switching and packet switching.
A : Circuit switching is a type of method for implementing a telecommunication network in which a dedicated path or physical connection is established before transmission of data. Dedicated connection allows full-duplex, fast, safe and reliable transmission of data. After the data transfer, the path is released. Example – voice communication (telephone etc.).
Packet switching is a digital networking method for (half-duplex) communication in which data is divided into small segments (called packets) which are transmitted over a medium that is shared between parties in a network. Example – data communication (internet etc.).
Q-22. What is Inter-Symbol Interference (ISI)?
A : Inter-Symbol Interference or ISI is defined as the crosstalk between the signals of the same channel/sub-channel which are separated in time by a finite interval. In simple terms, it is the distortion in the desired signal caused due to the interference by the signals of the same channel to which it belongs.
Q-23. What is Inter-Channel Interference (ICI)?
A : Inter-Channel Interference or ICI is defined as the distortion in the desired signal due to interference caused by the signals of other channels in the surrounding of the desired signal.
Q-24. What is Adjacent Channel Interference (ACI)?
A : Adjacent Channel Interference or ACI is the distortion in the desired signal caused due to interference by signals that are adjacent in frequency of the desired signal. ACI can be minimized through careful filtering and channel assignments.
Q-25. What is Near-Far Effect? Where does it happen?
A : Due to Adjacent Channel Interference (ACI) which is caused due to imperfect filters, nearby frequencies leak into the passband of the receiver. This problem can be particularly serious if a large number of channel users are transmitting in a very close to a subscriber receiver. This situation is referred to as Near-Far effect where a nearby transmitter captures the receiver of the subscriber and happens in the case of CDMA in which multiple users operate on the same frequency with different orthogonal codes. Any error in assigning the codes to the users can cause this problem.
PS: Aricent is acquired by Altran in 2018 and Altran is acquired by Capgemini in 2020.
Continued to Part 6